1. Field of the Invention
The present invention relates to antenna systems. More particularly, the present invention relates to a starfish mesh antenna and array thereof with increase bandwidth implemented with printed circuit board technology.
2. Description of the Prior Art
Generally, patch antenna systems are implemented with printed circuit board technology. Patch antenna systems are typically one-resonance antenna systems, and thus, operate within a limited bandwidth, such as up to ten percent. Accordingly, patch antenna systems are typically designed to operate within a specific frequency band. These types of antenna systems typically require that an individual or single patch antenna is provided to operate at each frequency.
A prior art narrow-band mesh antenna as an extension of the loop antenna published in xe2x80x9cIEEE Transactions on Antenna and Propagationxe2x80x9d, vol. AP-49, pp. 715-723, May 2001 is illustrated in FIG. 1a. The authors wrote in the abstract: xe2x80x9c . . . [t]he frequency bandwidth for VSWR=2 criterion is evaluated to be approximately 3% . . . [t]he frequency bandwidth for a 3 dB axial ratio criterion is calculated to be approximately 1%.xe2x80x9d The feeding points a,b,c, and d are connected to coax.
There is a need for a mesh antenna system implemented with printed circuit board technology. There is a need for a mesh antenna system that operates at a bandwidth of more than one octave. There is a need for a mesh antenna system that is low cost. There is a need for a mesh antenna system that can be implemented for use with satellites, radars, space-vehicles and aircrafts.
According to embodiments of the present invention, a broadband mesh antenna and a phased array broadband mesh antenna are provided. The antennas of the present invention are mesh antenna systems implemented with printed circuit board technology that operates with increased bandwidth more than one octave. The simulated data presented in the disclosure of the present invention, illustrates a single mesh antenna operable at a wide range of frequencies, such as between 250 MHz to 730 MHz. The mesh antenna can be scaled to other frequency bands employing a 2.92:1 coverage ratio.
According to an embodiment of the present invention, a broadband mesh antenna includes an element including a conductive surface. The conductive surface includes a) a symmetrically shaped conductive surface, such as a square loop, around a point corresponding to the center of the symmetrically shaped conductive surface, b) a first set of linear conductive surfaces extending away from the point corresponding to the center of the symmetrically shaped conductive surface, and c) a second set of linear conductive surfaces. Each linear conductive surface in the second set of linear conductive surfaces extends away from a point on a linear conductive surface in the first set of linear conductive surfaces to a corner of the symmetrically shaped conductive surface. The first set of linear conductive surfaces and second set of linear conductive surfaces enables the broadband mesh antenna to operate at a set of octaves.
According to an embodiment of the present invention, the broadband mesh antenna further includes a set of feed ports, such as four, symmetrically located around the point corresponding to the center of the symmetrically shaped conductive surface. A ground screen couples to the set of feed ports employing a corresponding set of feed lines, such as four coaxial lines. The ground screen is a distance h away from the element. The broadband mesh antenna can be provided within an box with an open top manufactured from structures such as wires and metal. The excitation of the broadband mesh antenna can be provided by coupling an inner conductor of each feed line to a feed port and coupling the outer conductors of each feed lines to the ground screen.
According to an embodiment of the present invention, a broadband mesh antenna includes an element including a conductive surface. The conductive surface includes a) a first symmetrically shaped conductive surface, such as a square loop, around a point corresponding to the center of the symmetrically shaped conductive surface, b) a first set of linear conductive surfaces extending away from the point corresponding to the center of the symmetrically shaped conductive surface, and c) a second symmetrically shaped conductive surface, such as a starfish, around a point corresponding to the center of the symmetrically shaped conductive surface. The first and second symmetrically shaped conductive surfaces enables the broadband mesh antenna operates at a first set of octaves.
According to an embodiment of the present invention, a broadband phased array mesh antenna includes a set of elements, each element in the set of elements including a conductive surface. Each conductive surface includes a) a symmetrically shaped conductive surface, such as a square loop, around a point corresponding to the center of the symmetrically shaped conductive surface, b) a first set of linear conductive surfaces extending away from the point corresponding to the center of the symmetrically shaped conductive surface, and c) a second set of linear conductive surfaces. Each linear conductive surface in the second set of linear conductive surfaces extends away from a point on a linear conductive surface in the first set of linear conductive surfaces to a corner of the symmetrically shaped conductive surface. The first set of linear conductive surfaces and second set of linear conductive surfaces enables the broadband mesh antenna to operate at a set of octaves.
According to an embodiment of the present invention, the broadband mesh antenna further includes each antenna element includes a set of feed ports, such as four, symmetrically located around the point corresponding to the center of the symmetrically shaped conductive surface. A ground screen couples to the set of feed ports employing a corresponding set of feed lines, such as four coaxial lines. The ground screen is a distance h away from the element. The broadband mesh antenna can be provided within an box with an open top manufactured from structures such as wires and metal.
According to an embodiment of the present invention, a phased broadband mesh array antenna includes a set of elements, each element in the set of elements including a conductive surface. Each conductive surface includes a) a first symmetrically shaped conductive surface, such as a square loop, around a point corresponding to the center of the symmetrically shaped conductive surface, b) a first set of linear conductive surfaces extending away from the point corresponding to the center of the symmetrically shaped conductive surface, and c) a second symmetrically shaped conductive surface, such as a starfish, around a point corresponding to the center of the symmetrically shaped conductive surface.